<!DOCTYPE html>
<title>Tests parsing of the anchor() function</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#anchor-pos">
<link rel="author" href="mailto:xiaochengh@chromium.org">
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../../css/support/parsing-testcommon.js"></script>

<script>
const anchorNames = [
  '',
  '--foo',
];

const insetProperties = [
  'left',
  'right',
  'top',
  'bottom',
  'inset-block-start',
  'inset-block-end',
  'inset-inline-start',
  'inset-inline-end',
];

const anchorSides = [
  'inside',
  'outside',
  'left',
  'right',
  'top',
  'bottom',
  'start',
  'end',
  'self-start',
  'self-end',
  'center',
  '50%',
  'calc(50%)',
  'min(50%, 100%)',
];

const fallbacks = [
  null,
  '1px',
  '50%',
  'calc(50% + 1px)',
  'anchor(left)',
  'anchor(--bar left)',
  'anchor(--bar left, anchor(--baz right))',
];

// Tests basic combinations
for (let property of insetProperties) {
  // Using a wrong anchor-side (e.g., `top: anchor(--foo left)`) doesn't cause a
  // parse error, but triggers the fallback when resolved.
  for (let name of anchorNames) {
    for (let side of anchorSides) {
      for (let fallback of fallbacks) {
        let value = `anchor(${name ? name + ' ' : ''}${side}${fallback ? ', ' + fallback : ''})`;
        test_valid_value(property, value);
        if (name) {
          // The <anchor-element> is allowed to appear after the <anchor-side>
          let value_flip_order = `anchor(${side} ${name}${fallback ? ', ' + fallback : ''})`;
          test_valid_value(property, value_flip_order, value);
        }
      }
    }
  }
}

// Tests that anchor() can be used in a calc tree
// Still follow the simplification process as outlined in https://drafts.csswg.org/css-values-4/#calc-simplification
test_valid_value('top', 'calc((anchor(--foo top) + anchor(--bar bottom)) / 2)', 'calc(0.5 * (anchor(--foo top) + anchor(--bar bottom)))');
test_valid_value('top', 'calc(0.5 * (anchor(--foo top) + anchor(--bar bottom)))');
test_valid_value('top', 'anchor(--foo top, calc(0.5 * anchor(--bar bottom)))');
test_valid_value('top', 'min(100px, 10%, anchor(--foo top), anchor(--bar bottom))');
</script>
